Rpm regulator for a fuel injection pump serving an internal combustion engine

ABSTRACT

In a fuel injection pump associated with an internal combustion engine, the fuel quantities injected during each pressure stroke on the one hand and the injection start on the other hand are separately regulated as a function of the engine-rpm by two groups of centrifugal weights, each group displacing a separate governor member moving independently from the other.

Unite States Patent [1 1 Hoimann Feb. 12, 1974 RPM REGULATOR FOR A FUELINJECTION PUMP SERVING AN INTERNAL COMBUSTION ENGINE [75] Inventor:

[73] Assignee: Robert Bosch GmbH, Stuttgart,

Germany [22] Filed: Aug. 15, 1972 [21] Appl. No.: 280,867

Karl Hofmann, Aldingen, Germany [30] Foreign Application Priority DataSept. 9, 1971 Germany 2145036 [52] US. C1.l23/139 AP, 123/139 AL,123/139 AR,

124/140 R [51] Int. Cl... F02m 59/20 [58] Field of Search 123/140 R, 140A, 139 BD [5 6] References Cited UNITED STATES PATENTS 3,673,996 7/1972Dreisin 123/139 BD 1,602,208 10/1926 Price 123/140 A 3,638,631 2/1972Eheim 123/140 A Primary ExaminerLaurence'M. Goodridge Attorney, Agent,or Firm-Edwin E. Greigg ABSTRACT In a fuel injection pump associatedwith an internal combustion engine, the fuel quantities injected duringeach pressure stroke on the one hand and the injection start on theother hand are separately regulated as a function of the engine-rpm bytwo groups of centrifugal weights, each group displacing a separategovernor member moving independently from the other.

4 Claims, 3 Drawing Figures RPM REGULATOR FOR A FUEL ENJECTION PUMPSERVING AN INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION Thisinvention relates to an rpm regulator for a fuel injection pumpassociated with an internal combustion engine and is of the type thatincludes a centrifugal governor having a first group of centrifugalweights actuating the fuel quantity control member of the fuel injectionpump and a second group of centrifugal weights affecting the position ofa timing member that determines the injection start during each pressurestroke of the fuel injection pump.

In a known rpm regulator of the aforenoted type, as disclosed, forexample, in US. Pat. No. 2,274,609, it is not possible to actuate thefuel quantity control member separately from the timing member for theentire rpm range.

OBJECT AND SUMMARY OF THE INVENTION although exemplary embodiment takenin conjunction 1 with the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic, partiallysectional view of the preferred embodiment with parts of the fuelinjection P p FIG. 2 is a view in the direction of the axis of rotation,of the arrangement of the centrifugal weights and FIG. 3 is an axialview of a part of the regulator and the fuel injection pump.

DESCRIPTION OF THE EMBODIMENT In an only symbolically illustratedhousing 1 of a fuel injection pump for a four-cylinder internalcombustion engine there journals a pump drive shaft 2. The latter iscoupled with a radial cam disc 3 which carries four cams 4 (that is, asmany cams as there are cylinders in the engine). The cam track of thecam disc 3 engages rollers 5 which, in turn, journal about pins 6stationarily supported in the housing 1. There is further provided apump-and-distributor member 8 which, at its driven end, has a collar 9which, in turn, is coupled by means of a pin 10 with the cam disc 3. I

Under the effect of a spring 11 the cam disc 3 is pressed intocontinuous contact with the rollers 5. The

pump-and-distributor member 8 slides in a pump body 12 which is closedby means of a plug 13.

The inner chamber 14 of the fuel injection pump is filled with slightlypressurized fuel taken from a source, not shown. From the chamber 14there extends an inlet channel 15 which cooperates with fourlongitudinal, axially parallel extending grooves 16 provided in thelateral face of the pump-and-distributor member 8. The longitudinalgrooves 16 are in communication with a pump work chamber 17 and with anannular groove 18 provided on the pump-and-distributor member 8. Fromthe annular groove 18 there extends a distributor groove 19 in thepump-and-distributor member 8 for cooperation with four outlet channels20 (only one shown).

The inlet channel 15 is offset with respect to the outlet channels 20 insuch a manner that, dependent upon the position of thepump-and-distributor member 8, either the inlet channel 15 communicateswith one of the axial grooves 16 or the distributor groove 19communicates with one of the outlet channels 20. Each of these outletchannels 20 leads to a spring-biased pressure valve 22 to which there iscoupled an injection conduit (not shown) leading to a fuel injectionnozzle (also not shown) associated with an engine cylinder.

From the pump work chamber 17 there extends, within thepump-and-distributor member 8, an axial channel 23 to a radial port 24and to four radial channels 25 (FIG. 3). A control sleeve 26 is mountedfor axial and angular displacement on the pump-and distributor member 8.The radial face 27 of the control sleeve 26 cooperates with the radialport 24. Into the other, opposite radial face of the control sleeve 26there is machined an oblique control surface 28 which cooperates withthe radial channels 25.

To the drive shaft 2 there is keyed a spur gear 29 which meshes with aspur gear 30. The latter is affixed to the hub of a cage 31 which isfixedly attached to a setting shaft 32 journaling in the housing 1. Inthe cage 31 there are swingably arranged two groups of centrifugalweights 33 and 34, respectively. As shown in FIG. 2, the first groupcomprises four centrifugal weights 33 which are in engagement with agovernor sleeve 35. The second group is formed of two centrifugalweights 34 which,,in turn, engage a governor sleeve 36. The governorsleeves 35 and 36 are telescopically disposed; the governor sleeve 35 isguided on the setting shaft 32.

The first group of centrifugal weights serves for the rpm-dependentalteration of the delivered fuel quanti ties of the fuel injection pumpand for this purpose actuates, through the governor sleeve 35, a lever37 which, after swinging freely along a short path, engages a lever 38.The levers 37 and 38 are connected to resetting springs 41 and 42, thebias of which is variable by means of alever 43. The latter is carriedat one end of a pin 44 supported in the housing 1. The other end of thepin 44 carries an arbitrarily adjustable setting lever 45 which, in itsshown terminal position, engages an abutment pin 46. I

The second group of centrifugal weights serves for shifting the startingmoment of the injection and for this purpose actuates through thegovernor sleeve 36 a lever 48 which is connected to a resetting spring49 attached to a post 50 fixedly secured to the housing 1.

The levers 37 and 38 are pivotally held by a pin 51. The lever 37 hastwo arms; its arm 37' carries a sphere 52 which projects into alongitudinal depression 53 provided in the control sleeve 26. The lever48 which also has two arms, is pivotableabout a support pin 54 andextends with its spherical end 48' into a circumferentially orienteddepression 55 provided in the control sleeve 26.

When the engine is running, the drive shaft 2 of the pump, the cam disc3 and the pump-and-distributor member 8 coupled to the drive shaft 2rotate with an rpm that is a function of the engine rpm. The cam disc 3,in cooperation with the rollers 5 causes an axial reciprocating motionof the pump-and-distributor member 8 in addition to its rotation. Thecam disc 3 is maintained in continuous contact with the rollers 5 byvirtue of the spring 11. The pump-and-distributor member 8 is shown inH0. 1 in its lower dead center. The pump work chamber 17 is charged withfuel through the inlet channel 15. As the cam disc 3 rotates, first theinlet channel is closed by the lateral face of the pumpand-distributormember 8, a precondition for starting, the effective pressure stroke ofthe pump-anddistributor member 8. During the course of the effectivepressure stroke fuel is delivered from the pump work chamber 17 throughthe channels 16 into the annular groove 18 and therefrom through thedistributor groove 19 into one of the outlet channels 20 and through theassociated pressure valve 22 to a fuel injection nozzle of the internalcombustion engine.

The beginning and the end of the injection is determined by virtue ofthe cooperation of the frontal face 27 of the control sleeve 26 with thechannel 24 and the control face 28 with one of the channels 25. Theeffective pressure stroke begins when the channel 24 is closed by thecontrol sleeve 26 and terminates when the control face 28 opens thechannel 25.

The duration of injection and thus the injected fuel quantities may bealtered by rotating the control sleeve 26 with the aid of the lever 37,37', whereas the beginning of injection may be shifted by means of anaxial displacement of the control sleeve 26 with the aid of the lever48.

The aforedescribed rpm regulator operates as follows:

As the pump drive shaft .2 rotates, the setting shaft 32 of the controlapparatus is also rotated by the spur gears 29 and 30. Thus, in case ofan rpm increase the centrifugal weights 33 and 34 move outwardly anddisplace the governor sleeves 35 and 36 to the right as viewed in FIG.1.

The governor sleeve 35, during its aforenoted rightward displacement,first causes the lever 37, 37 to pivot against the force of therelatively weak and soft spring 41 until the lever 37, 37 engages thelever 38. Since the lever 45 is in engagement with the abutment 46 andthe spring 42 has only a weak bias, the centrifugal weights 33, afterthe internal combustion engine is started, also cause a pivotal motionof the lever 38, so that the control sleeve 26 sets the oblique controlface 28 for a smaller fuel quantity. Thus, the fuel quantity will bedecreased from the starting fuel quantities to the quantities necessaryfor the idling run of the engine.

it is thus seen that with the adjusting lever 45 there may be set anarbitrary engine rpm which is maintained with the rpm regulator. Bymeans of the pivotal motion of this lever, the state of tensioning andthus the resetting force of the springs 41 and 42 is altered.Consequently, there is determined an rpm at which the centrifugalweights 33, after engagement of the lever 37, 37' with the lever 38,overcome the force of the spring 42 and lift the lever 38 from anabutment 56 which determines the full load fuel quantities. In thismanner the control sleeve 26 is again rotated, so that the obliquecontrol face 28 of the control sleeve 26 sets a fuel quantity which isnecessary for maintaining the desired rpm.

The two centrifugal weights 34 affecting the governor sleeve 36 pivotagainst the force of the spring 59 as the rpm increases and cause,through the governor sleeve 36, a pivotal motion of the lever 48 whichthus axially displaces the control sleeve 26. As a result, the positionof the radial face 27 with respect to the channel 24 changes and, as aresult, the moment of injection start of the fuel injection pump isvaried.

Since the two groups of centrifugal weights actuate separate governorsleeves 35 and 36, a quantity setting of the fuel injection pump ispossible throughout the entire rpm range independently from the settingof the injection start. In addition, the described rpm regulator is ofsimple, economical structure.

What is claimed is:

1. In an rpm regulator for a fuel injection pump serving an internalcombustion engine, said fuel injection pump being of the known type thathas (a) a rotary component having an engine-rpm dependent rotationalspeed, (b) a fuel quantity control member, the position of whichdetermines the fuel quantities delivered to said engine for injection,(c) a timing member, the position of which determines the movement ofinjection start during each pressure stroke of the pump, said rpmregulator being of the known type that has (a) a first group ofcentrifugal weights secured to said rotary component and affecting theposition of said fuel quantity control member, (b) a second group ofcentrifugal weights secured to said rotary component and affecting theposition of said timing member, (c) resetting spring means opposing theforce of said centrifugal weights exerted on said members, theimprovement comprising A. a first sleeve-like governor member connectedto said centrifugal weights forming said first group to be displaced bythe latter to an rpm-dependent extent,

B. a first coupling means connecting said first governor member to saidfuel quantity control member,

C. a second sleeve-like governor member connected to said centrifugalweights forming said second group to be displaced by the latter to anrpmdependent extent, said first and said second sleevelike governormembers being telescopic and displaceable independently from one anotherand D. a second coupling means connecting said second governor member tosaid timing member.

2. An improvement as defined in claim ll, including a setting shaftsupporting at least indirectly said centrifugal weights, said settingshaft having an axis about which said centrifugal weights rotate, saidinner governor sleeve being slidably disposed on said setting shaft.

3. An improvement as defined in claim 1, wherein said first and secondcoupling means are constituted by separate levers, said resetting springmeans engaging said separate levers.

4. An improvement as defined in claim 1, wherein said fuel injectionpump includes A. a pump body,

B. a pump work chamber provided in said pump body,

C. a pump-and-distributor member disposed at least partially in saidpump body and connected to said rotary component to be rotated by thelatter, said pump-and'distributor member cooperating with said pump workchanber,

D. means connected to said rotary component and saidpump-and-distributor member for causing axial reciprocation of thelatter,

6 v E. a channel means extending within said pump-andmined momentsdependent upon the position of distributor member, said channel meanscommuni-- said control sleeve, said control sleeve constituting eatingwith said pump work chamber and having a both said fuel quantity controlmember and said terminal opening on the lateral face of said pumptimingmember, said control sleeve being conand-distributor member and i 5nected to said first group of centrifugal weights F. acontrol sleevemovably mounted on said pumpthrough said first coupling means and tosaid secand-distributor member and opening and closing 0nd group ofcentrifugal weights through said secsaid channel means during rotationand reciproca- 0nd coupling means. tion of said pump-and-distributormember at deter-

1. In an rpm regulator for a fuel injection pump serving an internalcombustion engine, said fuel injection pump being of the known type thathas (a) a rotary component having an engine-rpm dependent rotationalspeed, (b) a fuel quantity control member, the position of whichdetermines the fuel quantities delivered to said engine for injection,(c) a timing member, the position of which determines the movement ofinjection start during each pressure stroke of the pump, said rpmregulator being of the known type tHat has (a) a first group ofcentrifugal weights secured to said rotary component and affecting theposition of said fuel quantity control member, (b) a second group ofcentrifugal weights secured to said rotary component and affecting theposition of said timing member, (c) resetting spring means opposing theforce of said centrifugal weights exerted on said members, theimprovement comprising A. a first sleeve-like governor member connectedto said centrifugal weights forming said first group to be displaced bythe latter to an rpm-dependent extent, B. a first coupling meansconnecting said first governor member to said fuel quantity controlmember, C. a second sleeve-like governor member connected to saidcentrifugal weights forming said second group to be displaced by thelatter to an rpm-dependent extent, said first and said secondsleeve-like governor members being telescopic and displaceableindependently from one another and D. a second coupling means connectingsaid second governor member to said timing member.
 2. An improvement asdefined in claim 1, including a setting shaft supporting at leastindirectly said centrifugal weights, said setting shaft having an axisabout which said centrifugal weights rotate, said inner governor sleevebeing slidably disposed on said setting shaft.
 3. An improvement asdefined in claim 1, wherein said first and second coupling means areconstituted by separate levers, said resetting spring means engagingsaid separate levers.
 4. An improvement as defined in claim 1, whereinsaid fuel injection pump includes A. a pump body, B. a pump work chamberprovided in said pump body, C. a pump-and-distributor member disposed atleast partially in said pump body and connected to said rotary componentto be rotated by the latter, said pump-and-distributor membercooperating with said pump work chanber, D. means connected to saidrotary component and said pump-and-distributor member for causing axialreciprocation of the latter, E. a channel means extending within saidpump-and-distributor member, said channel means communicating with saidpump work chamber and having a terminal opening on the lateral face ofsaid pump-and-distributor member and F. a control sleeve movably mountedon said pump-and-distributor member and opening and closing said channelmeans during rotation and reciprocation of said pump-and-distributormember at determined moments dependent upon the position of said controlsleeve, said control sleeve constituting both said fuel quantity controlmember and said timing member, said control sleeve being connected tosaid first group of centrifugal weights through said first couplingmeans and to said second group of centrifugal weights through saidsecond coupling means.